If I have a joint account with someone who has debt to another bank (I was unaware when signing up for the account — lesson learned!), will I be responsible for his debt?

You are not liable for debt that you did not agree to either by taking out the debt yourself or co-signing for a loan or debt. You may be asking if one bank can take money from your joint account. The answer is no or there would be little need for collection agencies. Companies would simply have their bank take the money from their customers bank accounts. There are forms and agreements that must be signed to allow this to happen.

Here are a couple of exceptions. When you set up a bank account you agree to allow your bank to take money from other accounts you have at their bank to satisfy your debt to the bank, such as loans and overdrawn accounts. Also, the IRS has powerful laws that allow them to seize your bank account for unpaid taxes.